Arcing chamber housings which are designed for circuit breakers and are able to be assembled from two separate housing modules for each power supply phase are disclosed, for example in European Patent No. B 1-542 636. These housings can be assembled simply and quickly. In addition, it is merely the relatively small arcing chamber housing that needs to be made of an arc-resistant material. On the other hand, the housing which is placed over the arcing chamber housings that correspond in number to the number of phases, can be made of a less expensive material. The disclosed housing modules are essentially constituted of two saucer-shaped housing parts, symmetrically disposed with respect to the median plane in the longitudinal direction of the arcing chamber housing. To assemble the arcing chamber, initially the contact members, arc splitters, etc. are arranged in one of the two saucer-shaped housing modules, and the second housing module, as the case may be, is then placed upon the first housing module and joined, e.g., riveted thereto. The disadvantage of the known arcing chamber housings is, inter alia, that the extinction chambers of arcing chamber housings of this kind are first formed when the two housing modules are joined. For that reason, it is not possible, as a rule, to perform a complete test for correct functioning of the extinction chambers prior to their assembly. To eliminate sources of error, in particular in the arcing chambers, it is often necessary to disassemble the entire arcing chamber when known arcing chamber housings are used.